There's plenty for Costa Rica to dance about after stunning Uruguay and Italy to clinch a place in the knockout stage of the World Cup.

When the World Cup draw was conducted, three groups stood out above all others as the toughest: B, D and G.

With the two 2010 finalists and South American power Chile in Group B, at least one very strong side was bound to go home. Few figured it'd be defending champion Spain, and even fewer figured that fate would be decided with a game to go in the group stage.

With European juggernauts Germany and Portugal joining eight-year nemesis Ghana in Group G, the USA surely faced an uphill battle to make it through to the knockout stage. Yet after ending the Ghanaian hex through John Brooks' header and with the right set of results this weekend, the Americans can punch their ticket as soon as Sunday.

It's been that kind of unpredictable, unthinkable World Cup. Favorites still alive, consider yourselves warned. Here are three thoughts on the consensus toughest groups in the competition and how they've played out thus far:

Costa Rica's showing can only help CONCACAF

All that talk about CONCACAF potentially losing a World Cup berth (or intercontinental playoff place at the very least) because of its lack of strength as a confederation sure seems ludicrous at this point, no?

Costa Rica -- playing without two injured, potential starters, lest we forget -- is stunningly through to the round of 16 with a game to spare, beating Uruguay and Italy and looking like the better team both times. Sure, Uruguay was without Luis Suarez in the 3-1 opener, but Uruguay is still littered with world-class talent and took a calculated gamble in having Suarez sit that game out, trying to sneak in a few more days of rest before his triumphant return to the field.

On Friday, Italy had no answers. Mario Balotelli missed a golden opportunity in the first half, but Los Ticos bottled up Andrea Pirlo and limited his effectiveness. Costa Rica also defended admirably, shaking off what likely should've been two penalties that weren't granted and got the goal it needed to go through. Combine Costa Rica's showing with Mexico (four points through two games, which includes holding Brazil to a 0-0 draw) and the USA (scoring 30 seconds in on Ghana, getting a late winner and positioning itself well), and CONCACAF is anything but a second-rate confederation in this tournament at the present time.

Factor in the international praise MLS referee Mark Geiger has received amid a rash of poor officiating, and one could make the argument this is CONCACAF's time to shine.

The schedule makes all the difference

While the teams in the draw make the difficulty, the schedule provides the navigation path, and that second, undervalued aspect of the draw is surely becoming pertinent now. What if Spain had played Australia in its first game? Assuming Spain did, and was able to accrue three points, would its fate have been different? It at least would've had a meaningful group finale instead of one that is less useful than a pre-World Cup preparation friendly.

What if the U.S. had drawn Portugal first and was getting a full-strength opponent? Instead of getting a Portugal side featuring Fabio Coentrao, Pepe and Hugo Almeida, the Americans are in line to face a Portugal side that's going to be missing about half its starting lineup (In all fairness, Portugal is facing a USA side without Jozy Altidore, with a broken-nosed Clint Dempsey and a slightly hamstrung Matt Besler). There is no guarantee that will translate into three points (or even one point) for the Americans, but it definitely changes the approach and outlook. Also, facing Ghana first instead of last in the group as it did in 2006: Did that change the psychological game? Elimination wasn't on the line no matter what happened. Perhaps that played into the U.S.' favor.

Of course, it's up to the teams to play out the string as it is drawn and deal with the consequences. With the way Costa Rica and England have played, for example, there's no certainty the Three Lions would have fared any better than Uruguay or Italy did had it played the Ticos first instead of last.

This is a tournament for the non-traditional sides

The knockout stage is shaping up to be one that features more teams unaccustomed to being there than ever. Spain is toast, its last group game meaning absolutely nothing. England is out, failing to make the knockout stage for the first time since 1958. One of Group D's favorites, Italy or Uruguay, is going to be out depending on how the two squads' do-or-die finale unfolds.

Sure, the Netherlands making the final 16 is familiar, but consider how many thought the Oranje were due for a down-tick in fortune given their group. Meanwhile, Chile and Costa Rica have already cemented their places in the final 16. Colombia, which hadn't reached the knockout stage since 1990, is back.

The Ivory Coast is a result away from reaching the knockout stage for the first time ever. Host Brazil is almost certain to reach the next stage, but it's been anything but a cakewalk. With the way traditional powers are crumbling and non-traditional sides are thriving, this is truly as entertaining, unpredictable and wide open a World Cup as anyone could have anticipated.